Magnetic drop hammer



Feb. 21, 1928. 1,659,594

T. FARMER ET AL MAGNETIC DROP HAMMER Filed Aug. 15. 1926 l 31mm aoh asfryer; f 6 37/ $6717.59

Patented Feb. 21, 1928.

UNITED STATES PATENT OFFICE.

THOMAS FABMER, OF BIRMINGHAM, AND CARL H. SORENSEN, OF DETROIT, MICHIGAN.

MAGNETIC DROP HAMMER.

Application filed August 13, 1926. Serial No. 129,102.

This invention relates to drop hammers and has special reference to that type of blow delivering machines wherein a blow instrumentality or ram proper is elevated by power and dropped to deliver a blow. For elevating purposes the ram is equipped with a board engageable by two or more driven rollers and the board is generally made of \\'ood, laminated or otherwise so as to possess a degree of flexibility. Such boards are subjected to considerable wear, stresses and st 'ains which cause the boards to crack or become injured to such an extent as to be useless. Board replacement is an expensive item in the operation of a drop hammer in addition to the time lost incident to replacement.

()ur invention aims to provide a drop hammer wherein a driven electro-magnetic member is utilized for raising a ram, and wherein a metallic board is used in lieu of the usual wood board. As a result, we have a drop hammer that is just as safe and positive as the usual drop hammer, but more durable and less expensive to maintain in an operable condition.

Our invention further aims to provide an electro-n'uignetic rotary member for raising a drop hammer board and, by virtue of mag' netic forces being utilized for establishing an operative engagement between the member and the board, a switch may be employed for controlling the energizing of the magnetic member.

Our invention in its broadest aspect involves opposed members one or both of which are driven and magnetized, for lifting an interposed hammer element. With this understanding of the principle involved, we have illustrated, by the way of an example, a conventional form of drop hammer, but would have it understood that our invention is applicable to various types of hammers in which a ram lifting element is raised to drop by gravity.

In the drawings,

Figure 1 is a vertical sectional view of a drop hammer equipped with our lifting means;

Fig. 2 is a front elevation of a portion of the same;

Fig. 3 is a plan of the hammer, and

Fig. 4 is a diagrammatic view showing superposed lifting means.

In the drawing, the reference numeral 1 denotes a frame having an anvil 2 and guideways 23 for a ram or blow instrumentality 4 adapted to be raised and dropped to produce a blow on a piece of work placed on the anvil 2.

On the upperend of the frame are bearings 2 and 3 one or bothof which is provided with angularly disposed slots or ways 24 for the endsof a rotatable shaft 5 and mounted on said shaft is a roller or metallic memher 6.

Journaled in the bearings 2 and 3 is a driven shaft 7 having one end thereof provided with a belt Wheel 8 for a belt 9, which together with the wheel 8 represent power transmission means from a suitable source of power adapted to drive the shaft 7. Mounted on the shaft 7 and opposed to the rotary member 6 is an electro-magnetic member 10 including a series of coils 11 having leading-out conductors 12 and 13 with the latter connected to the shaft 9 or suitably grounded. The conductor 12 is connected to a ring 14 supported fromthe shaft 7, and suitably insulated therefrom. This ring is engaged by a brush or finger 1f) supported from the upper end of the frame 1 and suitably insulated therefrom, as at 16, with said brush or finger connected by a conductor 17 to a conventional form of switch 18 at the base of. the frame 1. The switch 18 has leading-in conductors 19 from a suitable source of electrical energy and said switch may be of that type that can be conveniently closed or actuated by a treadle 20. The rain 4 is provided with a metallic board 21 constituting a lifting member interposed between the rotary members 6 and 10 with the rotary member 6 normally engaging one face of the board 21 and the rotary member 10 engaging the opposite face of said board. By virtue of the inclined slots or ways 24 the rotary member 6 bears against the face of the board 21 by gravity but may yield or recede so as to exert no material pressure against the board 21 when descending. This will permit of the board 21 adjusting itself between the rotary members 6 and 10 when dropping so that there will be no material interference by the unenergized driven member 10. With this member revolving in a clockwise direction, considering Fig. 1, it is only necessary to close the switch 18 to energize the magnetic member 10 at which time there is a tractive force between the board 21 and the members (5 and 10 WlllCll causes said members to cooperate in lifting the board Qlto a desired height. The c sation in the lifting of the board takes place when the switch 18a is opened cutting oil the current to the coils ll of the rotary member 10. 'l. he foregoing is suggestive of placing sets of rotary members in superposed relation, as shown in Fig. t and in some instances there may be a reversal of our arrangement wherein the board might be equipped with. coils adapted to be energized to facilitate lifting the hammer. Then again, opposed inagnetic members 10 may be used for engaging opposite faces of the board 21. i

- Obviously the hammer board'made of metal may possess a desired degree of flexibility and be inherently of greater strength and durability than an ordinary wooden board.

lVe do not care to confine our invention to details of construction in connection w'th the electro-magnetic lifting member, its electrical connections and control, so with this understanding the structural elements are susceptible to such variations and modifications as are permissible by the appended claims.

What we claim is 1. A drop hammer including a metallic lifting board, and rotary electrical means in contact with the metallic lifting board to facilitate lifting said'board.

2. A drop hammer as called for in claim 1, 7

wherein said means includes, a driven rotary electro-magnetic member.

3. In a drop hammer, opposed members, one of which is revolved and produces magnetic forces, andram lifting means contacting with said members and shiftable by said members. 7

4. In a drop hammer, a. metallic ram lifting element, and magnetic means rollable against said element and adapted to lift said element.

l5. Lifting means for adrop hammer comprising a metallic board, a rotary member freely engaging one face of said board, a driven rotary member adapted to engage the other face of said board, and means for establishing magnetic attraction between said board and driven rotary member, so that both of said rotary members may cooperate in lifting said board.

6. A drop hammer as called for in claim 5, and means adapted for conducting and 

